Patellar Cartilage

patellar cartilage a cartilaginous process borne on the medial side of the patella of horses and cattle. patellar fossa the depression in the anterior face of the vitreous humor in which the lens sits. patellar ligament the continuation of the central portion of the tendon of the quadriceps femoris muscle distal to the patella, extending from the patella to the tuberosity of the tibia; it is single in carnivores, pigs and sheep and triple in horses and cattle; called also patellar tendon. patellar ligament desmotomy section of the medial patellar ligament for relief of upward luxation of the patella in horses (and rarely, cattle). patellar luxation, patellar dislocation 1. a common, congenital or acquired orthopedic abnormality in dogs, causing mild to severe, continuous or intermittent lameness. Medial luxation is more common in toy or miniature breeds, often as an inherited defect and frequently associated with structural abnormalities of the distal femur and proximal tibia. Lateral luxation is less frequent, and occurs more often in large breeds associated with genu valgum. 2. Upward luxation and fixation in cattle presents with temporary or permanent stiffness and extension of the affected hindlimb and the animal drags the tip of the toe. More common in Brahman cattle. The cause is not known. Correction is by medial patella desmotomy. patellar reflex involuntary contraction of the quadriceps muscle and jerky extension of the hindlimb when the patellar ligament is sharply tapped. It is often used as a test of nervous system function. Absence of the reflex, together with deficient muscle tone in the limb, suggests paralysis or paresis due to lower motor neuron lesion. Called also quadriceps reflex.

Testing the patellar reflex. By permission from Sharp NJH, Small Animal Spinal Disorders, Mosby, 2004

patellar tendon see patellar ligament (above).

Patellar dislocation: Orthopedics A subluxation, usually lateral, of the patella, due to a sudden change in direction while running and the knee is under stress; may follow injury, accompanied by pain and inability to walk. See GLC7. Patellar desmotomy: It is surgical technique used when there is indication of upward luxation of patella in cattles. This condition occurred in animals (cattle and Buffaloes) which are living in Highline areas or hilly areas. Animal usually drag its legs when it gets up and start walking. This operation is done 1.5 to 2” above the anterior tuberosity of tibia close to the insertion of medial ligament in a depression between middle and medial ligament. Local infiltration anesthesia is used under the supervision of expert veterinary surgeon. In this operation, Animal is casted and secured in lateral recumbancy on affected side. A rope has tied to the affected limb at the pastern & pulled backward in the extended position .The area prepared

aseptically. A stab incision is made into the skin with B.P.handle no.3 (blade no.1).the medial ligament is cut carefully starting from anterior border of ligament towards the skin. An appreciable gap will be formed between the cut edges & confirm the same with the thumb. Apply Tr.Iodine at the site. Generally post operative care has not required .

introduction: Patellar fixation is one of the main functional disorders of the tibia-femoral-patellar articulation (knee joint) in cattle (1) characterized by temporary or permanent dislocation of the patella from its regular position during locomotion (2). Such dislocation may be dorsal, lateral or medial, causing a dorsal, lateral or medial patellar fixation, respectively (3,4,5). The major potential factors for patellar fixation in cattle are nutrition deficiency, exploitation activity, breed and genetic tendency, external traumas, intense contraction of the crural triceps muscle and morphological changes of the trochlea and medial condyle of the femur (2, 6, 7, 8, 9, 10 ). Lameness after extended rest is the most typical sign (7). The fixation invokes subtle extension of the limb, phalangeal flexion so that the animal drags the tip of the hoof (3). Diagnosis is based upon anamnesis, clinical signs and local palpation (3, 9), radiography may also be useful (11, 12). Ultrasonography may be employed for studying disorders such as those of the tibia-femoralpatellar articulation (13). Medial patellar desmotomy is frequently used in the treatment of dorsal patellar fixation (6 , 14). The use of exercises and injection of low concentration iodine solution into the femuropatellar articulation as an alternative treatment has also been reported (2,5,9). This present study is aimed to establish the clinical diagnosis and prevalence of dorsal patellar fixation in cattle, to evaluate the efficiency of the surgical treatment and to provide data which may be used to elucidate the etiopathogenesis of this condition

Materials and Methods During two seasons of the year, the rainy and dry, 183 rural properties were visited from 1990 to 2002, including approximately 106 300 animals, which 72% were females and 28% males. Half of them were evaluated in the rainy season, and the other half in the dry season. Patellar dorsal fixation was clinically diagnosed, in 309 animals of both sexes, 4 to 6 years of age and of different breeds (Bos indicus, Bos taurus, crossbreds and buffaloes), usage and reproductive categories. The animals were raised extensively on pastures, and received supplementary nutrition during the dry season. The preoperative care consisted of a 12 hours fast. The animals were cast in lateral recumbency, the limbs were extended and held by ropes. The limb to be operated was kept tractioned, remained at about 1m (3,3 ft) from the ground. A cushion was placed under the scapular area. Tranquilization was achieved with 0.1 mg/kg live weight Xylazine hydrochloride1, intramuscular on 267 animals while the rest tranquilization was not necessary. The tibia-femoral-patellar articulation area was appropriately prepared, and antisepsis was done by a disinfectant solution containing iodophor2, diluted on water as recommended (15). Local anesthesia was achieved in all animals by infiltrating approximately 20 ml of lidocaine hydrochloride3 into the gap located between tibia crest and the medial and intermediate patellar ligaments.

By placing the thumb and the medium finger respectively at the tibial tuberosity and at the upper spot of the femoral medial trochleal crest, the medium point between these two anatomic references was established using the index finger. This procedure facilitated the identification of the medial patellar ligament. After an incision of about 5 cm on the skin, at the area indicated by the index finger, the subcutaneous connective tissue was withdrawn, as well as the fasciae, yielding complete visualization of the medial patellar ligament. Next, a curved haemostatic clamp was placed between the ligament and the pericapsular connective tissue, in order to fix the ligament and make its sectioning easier. After the section of the ligament, was fixed several times to ensure that the problem was completely solved. Closure was made on two levels. First, the muscle fasciae were brought closer by an X stitch using simple catgut number 1, and, on the second level, dermorraphy was made using cotton 000 suture using simple separated sutures. The postoperative antibiotic therapy consisted of penicillin-G-benzathine4 at a dosage of 20 000 IU/ Kg live weight, every 48 hours on five occasions. Daily dressings were made with healing paste of zinc oxide, pine oil, vitamin A, sulfanilamide and triclorfon5. The removal of the sutures was recommended 10th to 12th days postoperatively.

The farmers (owners) were given a questionnaire on the affected animals. The questions concerned information about their age,sex, breed, lactating period, pregnancy, spontaneous recovery, diet and nutritional supplement, soil characteristics. For statistical analysis, Chi-square test with continuance correction was employed, so as to verify any associations of the frequency of dorsal patellar fixation occurrence with dry and rainy seasons and sex. When the Chi-square value was significant, the association coefficient was calculated to measure its magnitude (16). The confidence interval (95%) was calculated for the prevalence of dorsal patellar fixation during the study period (17).

Conclusions These results demonstrate that the surgical technique of medial patellar desmotomy, with the animal extended in lateral recumbency was effective and performed easily. As for the possible triggering factors, breed predisposition was not observed. Females were more susceptible, especially those which had just calved. Finally, nutritional deficiency seems to be the most important factor affecting its pathogenesis.